Understanding NFPA 72

NFPA's signaling standards date back to 1898. The 1993 edition of NFPA 72, National Fire Alarm Code was a consolidation of all of the fire alarm system-related installation standards published previously as separate documents. NFPA 72 covers the application, installation, location, performance and maintenance of fire alarm systems and their components.

A common misconception is that NFPA 72 requires a fire alarm system to be installed in all buildings. The requirement for a fire alarm system rests with the building codes. The purpose of the code is to “define the means of signal initiation, transmission, notification, and annunciation; the levels of performance; and the reliability of the various types of fire alarm systems.” It also defines the features associated with these systems and provides information necessary to modify or upgrade an existing system to meet the requirements of a particular system classification.

The National Fire Alarm Code “establishes the minimum required levels of performance, extent of redundancy, and quality of installation but does not establish the only methods by which these requirements are to be achieved.” Although the code only applies to the installation of new systems and is not retroactive, the Testing, Maintenance and Inspection chapter states, “The requirements of this chapter shall apply to both new and existing systems.” This requirement is important for those contractors who maintain and test fire alarm systems on a continuing basis. There is another option that allows the authority having jurisdiction (AHJ) to determine if the existing situation involves a distinct hazard to life or property, then retroactive application of the provisions of the code is allowed.

The 2002 edition reflects a number of technical revisions throughout the code. Some of the most important new requirements address impairments to fire alarm systems, additional requirements concerning the review and approval of performance-based detection system designs, revision of the rules for system survivability from attack by fire, the introduction of rules for an alternate approach for audible signaling, the addition of requirements to address performance-based designs for visible signaling, the relocation of testing and maintenance requirements for single- and multiple-station alarms and household fire alarm systems to the testing and maintenance chapter, and revisions to re-establish the prescriptive rules for household fire-warning equipment.

Conveniently, all of the fire alarm system installation requirements that must be followed are in one code. The wiring requirements are, of course, still contained in the NEC. Because you may not work on fire alarm systems on a daily basis, you need to be aware of these key changes in the code.

When you work on a system, you inherently cause impairments. As stated in Annex “A” of NFPA 72, “the term impairments encompass (sic) a broad range of circumstances wherein a fire alarm system or portion thereof is taken out of service for a variety of reasons. Impairments can be limited to specific initiating devices and/or functions (e.g., disconnecting the supervising station connection during system testing), or they can involve taking entire systems or portions of systems out of service.”

The code requires the system owner or designated representative be notified when a fire alarm system is impaired. It also requires a record be maintained by the system owner or designated representative for a period of one year from the date the impairment is corrected. And where required, mitigating measures acceptable to the AHJ must be implemented for the period the system is impaired.

The need for these measures is typically determined by the AHJ on a case-by-case basis. The AHJ will consider the building, occupancy type, nature and duration of impairment, building occupancy level during impairment period, active work being conducted on the fire alarm system during the impairment, condition of other fire protection systems and features (e.g., sprinklers, the number of fire compartments, etc.), and hazards and assets at risk to determine what mitigating measures are appropriate. These could range from occupant notification and instructions as to procedures to follow in a fire emergency during the impairment to a full-time fire watch.

If during a fire alarm system test a defect or malfunction is found, it must be corrected immediately and if not corrected at the conclusion of a system inspection, testing or maintenance, the system owner or the designated representative must be informed of the impairment in writing within 24 hours.

Every time your electricians work on a fire alarm system, the impact of impairments needs to be considered. As we explore NFPA 72-2002, other important changes will be highlighted to ensure you are prepared to accomplish your work in a safe and professional manner. EC

MOORE, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a co-editor of the current National Fire Alarm Code Handbook. Moore is a principal with Hughes Associates Inc. at the Warwick, R.I., office.